<!DOCTYPE html>
<html>

<head>
  <meta charset="UTF-8">
  <style>
    table,
    th,
    td {
      border: 1px solid black;
      border-collapse: collapse;
    }
  </style>
</head>

<body>

  <table>
    <tr>
      <th>行1列1</th>
      <th>行1列2</th>
    </tr>
    <tr>
      <td>行2列1</td>
      <td>行2列2</td>
    </tr>
  </table>

</body>

</html>